Automotive lighting is significantly regulated by the federal government. Emitted light patterns, particularly those used in exterior lighting applications, must be controlled to meet federal regulations. The regulations exist to ensure the safety of drivers, pedestrians and other drivers in the environment of the vehicle. LED source technologies are rapidly becoming an efficient alternative to incandescent light bulb technologies. However, LED sources have a significant drawback in that they produce highly directional light. The directional nature of the light produced by LED sources has inhibited the development of LED-based lighting assemblies that can meet federal regulations, particularly in vehicular exterior lighting applications.
An LED source significantly differs from an incandescent light source in the form of the light it produces. Whereas light emanates from an incandescent light bulb in nearly 360°, light is emitted from an LED from one surface in the form of a cone (solid angle). Near-field lenses (NFLs) are used today to collimate the cone (solid angle) of light generated by an LED, but do little to increase the spread of light comparable to that produced by an incandescent bulb. Further, LED-based light that is collimated by a conventional NFL does not possess a focal point, usually a pre-requisite for engineering other components, such as reflectors, that can also be employed in vehicular exterior lighting applications.
Accordingly, there is a need for an LED-based lighting assembly that can substantially replicate the light spread of an incandescent bulb and facilitate various packaging for use in certain applications, particularly vehicular exterior lighting applications.